[PATCH] fuse: use asynchronous READ requests for readpages
This patch changes fuse_readpages() to send READ requests asynchronously.
This makes it possible for userspace filesystems to utilize the kernel
readahead logic instead of having to implement their own (resulting in double
caching).
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 4a0b0f9..a7ef5e7 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -265,7 +265,7 @@
req->file = file;
req->in.numargs = 1;
req->in.args[0].size = sizeof(struct fuse_read_in);
- req->in.args[0].value = &inarg;
+ req->in.args[0].value = inarg;
req->out.argpages = 1;
req->out.argvar = 1;
req->out.numargs = 1;
@@ -311,21 +311,33 @@
return err;
}
-static int fuse_send_readpages(struct fuse_req *req, struct file *file,
- struct inode *inode)
+static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
{
- loff_t pos = page_offset(req->pages[0]);
- size_t count = req->num_pages << PAGE_CACHE_SHIFT;
- unsigned i;
- req->out.page_zeroing = 1;
- fuse_send_read(req, file, inode, pos, count);
+ int i;
+
+ fuse_invalidate_attr(req->pages[0]->mapping->host); /* atime changed */
+
for (i = 0; i < req->num_pages; i++) {
struct page *page = req->pages[i];
if (!req->out.h.error)
SetPageUptodate(page);
+ else
+ SetPageError(page);
unlock_page(page);
}
- return req->out.h.error;
+ fuse_put_request(fc, req);
+}
+
+static void fuse_send_readpages(struct fuse_req *req, struct file *file,
+ struct inode *inode)
+{
+ struct fuse_conn *fc = get_fuse_conn(inode);
+ loff_t pos = page_offset(req->pages[0]);
+ size_t count = req->num_pages << PAGE_CACHE_SHIFT;
+ req->out.page_zeroing = 1;
+ req->end = fuse_readpages_end;
+ fuse_read_fill(req, file, inode, pos, count, FUSE_READ);
+ request_send_background(fc, req);
}
struct fuse_readpages_data {
@@ -345,12 +357,12 @@
(req->num_pages == FUSE_MAX_PAGES_PER_REQ ||
(req->num_pages + 1) * PAGE_CACHE_SIZE > fc->max_read ||
req->pages[req->num_pages - 1]->index + 1 != page->index)) {
- int err = fuse_send_readpages(req, data->file, inode);
- if (err) {
+ fuse_send_readpages(req, data->file, inode);
+ data->req = req = fuse_get_request(fc);
+ if (!req) {
unlock_page(page);
- return err;
+ return -EINTR;
}
- fuse_reset_request(req);
}
req->pages[req->num_pages] = page;
req->num_pages ++;
@@ -375,10 +387,8 @@
return -EINTR;
err = read_cache_pages(mapping, pages, fuse_readpages_fill, &data);
- if (!err && data.req->num_pages)
- err = fuse_send_readpages(data.req, file, inode);
- fuse_put_request(fc, data.req);
- fuse_invalidate_attr(inode); /* atime changed */
+ if (!err)
+ fuse_send_readpages(data.req, file, inode);
return err;
}